TIDT272 April   2022

 

  1.   Description
  2.   Features
  3.   Applications
  4. 1Test Prerequisites
    1. 1.1 Voltage and Current Requirements
    2. 1.2 Considerations
    3. 1.3 Dimensions
  5. 2Testing and Results
    1. 2.1 Efficiency Graphs
    2. 2.2 Efficiency Data
    3. 2.3 Load Regulation
      1. 2.3.1 Primary Output
      2. 2.3.2 Secondary Outputs
        1. 2.3.2.1 Positive Outputs
        2. 2.3.2.2 Negative Outputs
    4. 2.4 Line Regulation
      1. 2.4.1 Primary Output
      2. 2.4.2 Secondary Outputs
        1. 2.4.2.1 Positive Outputs
        2. 2.4.2.2 Negative Outputs
    5. 2.5 Thermal Images
    6. 2.6 Bode Plots
      1. 2.6.1 5.5-V Input Voltage
      2. 2.6.2 12-V Input Voltage
  6. 3Waveforms
    1. 3.1 Switching
      1. 3.1.1 Q1 Drain to GND
      2. 3.1.2 Q1 Gate to GND
      3. 3.1.3 Diode D12
      4. 3.1.4 Diode D9
    2. 3.2 Output Voltage Ripple
      1. 3.2.1 Primary 10 V (Auxiliary)
      2. 3.2.2 Secondary +15 V
      3. 3.2.3 Secondary –5 V
    3. 3.3 Input Voltage Ripple
    4. 3.4 Start-Up Sequence
    5. 3.5 Shutdown Sequence

Description

This design introduces a tiny isolated auxiliary power supply used to supply automotive IGBT drive. The three isolated outputs support three gate controls, each output delivers +15 V and –5 V. An additional +10-V output is provided on the primary side. To simplify transformer windings, a virtual ground by ZENER diodes is implemented on the secondary side and well suited for symmetrical loading.

The flyback converter itself supports input voltage cranking as low as 5 Vmin and load dump up to
42 Vmax.